Superconducting Technology Assessment Position Papers

The challenges to extending the delivered computing capabilities of semiconductor technology through Moore's Law, while manageable in the short term, may prove difficult or possibly impractical in the long term. Even now, the complex interplay of power and performance is resulting in significant changes in previous trends. Clock rates of commodity microprocessors are flattening even as multi-core chips are emerging as the norm for next generation systems. While conventional wisdom has dictated an assumption of continued adherence to the pure CMOS tradition of the last decade and more, the supercomputing community must consider the possibility of alternative technologies, at least in combination with more conventional devices. More than just changing or augmenting the technology base, new architecture structures and programming models may need to be considered and multiple levels to exploit the potential of such advances. This panel addresses these issues with a focus on one possible alternative technology: superconductor devices. Rapid Single Flux Quantum (RSFQ) logic exhibits operational properties in terms of performance and power that now positions it as a potential future leader among alternative digital technologies to augment semiconductor components in hybrid systems. But it is also challenged by lack of maturity and commercial market as well as its reliance on extreme operational temperature regimes. This panel brings together leaders in the fields of technology and computer architecture to consider the possible strategies and potential viability of superconductor based supercomputing. RSFQ technology may deliver clock rates in excess of an order of magnitude that of the corresponding semiconductor logic and with dramatically reduced power requirements. Further, at least in principle, it is easier to fabricate than heavily doped based semiconductor device fabrication processes. Nonetheless, in spite of decades of research and experience with small fabrication lines, it has not managed to challenge the prevailing semiconductor technologies. However, the increasing difficulties to sustaining current level of growth in density and performance of CMOS within practical power constraints may change this. This panel considers critical issues of technology and architecture and how RSFQ may contribute effectively to future supercomputing next decade. Four major topics will be addressed: 1. superconductor technology 2. micro-architecture using RSFQ 3. hybrid memory systems 4. system architecture incorporating superconductor components Superconductor technology, its viability and capability, will be discussed by Arnold Silver, the inventor of the original single flux quantum electronic circuits and long-time leader in the field at TRW. Designing micro-architectures using RSFQ devices …